Generics [uk] Ltd (t/a Mylan) v Yeda Research and Development Co Ltd & Anor

In patent disputes, a claim may have a fuzzy boundary without being ambiguous or insufficient. Claims must be construed purposively, using the specification and common general knowledge, while giving effect to deliberate limitations. For an alleged arbitrary selection, the specification must disclose enough to make it plausible that the selection has the claimed technical significance. Post-dated evidence may confirm plausibility, but cannot create an undisclosed technical effect or retrospectively establish obviousness. A patent is not insufficient merely because a specified analytical technique has inherent measurement variability, provided the skilled person can perform the invention without undue burden. The patent was valid and the proposed generic product would infringe.

Mylan sought revocation of European Patent (UK) No. 0 762 888 and a declaration that its proposed generic glatiramer acetate product would not infringe. The patent concerned copolymer-1 fractions with specified molecular-weight characteristics and a process using hydrobromic acid deprotection.

The issues included priority, construction, obviousness over Teitelbaum 1971, Bornstein 1987 and Johnson 1994, insufficiency, added matter and infringement.

1. Construction. The claims were construed through the eyes of the skilled team, reading the specification purposively and with a mind willing to understand. “Approximately 6:2:5:1” had a fuzzy boundary but was not ambiguous. “Fraction” was not confined to material obtained by separation. “Average molecular weight” meant peak molecular weight (M_p) in the context of the patent. The molecular-weight percentages referred to molar fraction. The omitted word “over” in claim 4 was an obvious drafting error, and claim 7 did not require a fresh small-scale reaction for every batch.
2. Priority. Claims 3, 6 and 12 were not entitled to the priority date because the claimed combinations were not directly and unambiguously disclosed in the priority document.
3. Obviousness. Applying the structured Pozzoli v BDMO SA approach, the product claims were not obvious over Bornstein 1987 or Johnson 1994. The process claims were not obvious over Teitelbaum 1971: an ordinary skilled chemist would more likely treat molecular-weight loss during HBr deprotection as undesirable degradation than exploit it to control molecular weight.
4. Technical contribution and insufficiency. The patent made it plausible that the claimed material reduced relevant adverse effects. Post-dated clinical evidence could not establish obviousness or disprove a plausible technical effect. The skilled person could select a suitable SEC mobile phase and calibration method without undue burden.
5. Outcome. The patent was not invalid for obviousness, insufficiency or added matter. Mylan’s product fell within the claims and would infringe.